From 6637f9069c8bd819edc175cca13b667861aa3a0b Mon Sep 17 00:00:00 2001 From: David Heinemeier Hansson Date: Wed, 10 Oct 2007 17:35:10 +0000 Subject: Extracted sanitization methods from TextHelper to SanitizeHelper [DHH] Changed SanitizeHelper#sanitize to only allow the custom attributes and tags when specified in the call [DHH] git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@7825 5ecf4fe2-1ee6-0310-87b1-e25e094e27de --- .../lib/action_view/helpers/sanitize_helper.rb | 325 +++++++++++++++++++++ actionpack/lib/action_view/helpers/text_helper.rb | 309 +------------------- 2 files changed, 326 insertions(+), 308 deletions(-) create mode 100644 actionpack/lib/action_view/helpers/sanitize_helper.rb (limited to 'actionpack/lib/action_view/helpers') diff --git a/actionpack/lib/action_view/helpers/sanitize_helper.rb b/actionpack/lib/action_view/helpers/sanitize_helper.rb new file mode 100644 index 0000000000..e67abd9f67 --- /dev/null +++ b/actionpack/lib/action_view/helpers/sanitize_helper.rb @@ -0,0 +1,325 @@ +require 'action_view/helpers/tag_helper' +require 'html/document' + +module ActionView + module Helpers #:nodoc: + # The SanitizeHelper module provides a set of methods for scrubbing text of undesired HTML elements. + # These helper methods extend ActionView making them callable within your template files. + module SanitizeHelper + def self.included(base) + base.extend(ClassMethods) + end + + # This #sanitize helper will html encode all tags and strip all attributes that aren't specifically allowed. + # It also strips href/src tags with invalid protocols, like javascript: especially. It does its best to counter any + # tricks that hackers may use, like throwing in unicode/ascii/hex values to get past the javascript: filters. Check out + # the extensive test suite. + # + # <%= sanitize @article.body %> + # + # You can add or remove tags/attributes if you want to customize it a bit. See ActionView::Base for full docs on the + # available options. You can add tags/attributes for single uses of #sanitize by passing either the :attributes or :tags options: + # + # Normal Use + # + # <%= sanitize @article.body %> + # + # Custom Use (only the mentioned tags and attributes are allowed, nothing else) + # + # <%= sanitize @article.body, :tags => %w(table tr td), :attributes => %w(id class style) + # + # Add table tags to the default allowed tags + # + # Rails::Initializer.run do |config| + # config.action_view.sanitized_allowed_tags = 'table', 'tr', 'td' + # end + # + # Remove tags to the default allowed tags + # + # Rails::Initializer.run do |config| + # config.after_initialize do + # ActionView::Base.sanitized_allowed_tags.delete 'div' + # end + # end + # + # Change allowed default attributes + # + # Rails::Initializer.run do |config| + # config.action_view.sanitized_allowed_attributes = 'id', 'class', 'style' + # end + # + def sanitize(html, options = {}) + return html if html.blank? || !html.include?('<') + + attrs = options[:attributes] || sanitized_allowed_attributes + tags = options[:tags] || sanitized_allowed_tags + + returning [] do |new_text| + tokenizer = HTML::Tokenizer.new(html) + parent = [] + + while token = tokenizer.next + node = HTML::Node.parse(nil, 0, 0, token, false) + + new_text << case node + when HTML::Tag + if node.closing == :close + parent.shift + else + parent.unshift node.name + end + + node.attributes.keys.each do |attr_name| + value = node.attributes[attr_name].to_s + + if !attrs.include?(attr_name) || contains_bad_protocols?(attr_name, value) + node.attributes.delete(attr_name) + else + node.attributes[attr_name] = attr_name == 'style' ? sanitize_css(value) : CGI::escapeHTML(value) + end + end if node.attributes + + tags.include?(node.name) ? node : nil + else + sanitized_bad_tags.include?(parent.first) ? nil : node.to_s.gsub(/these tags!") + # # => Strip these tags! + # + # strip_tags("Bold no more! See more here...") + # # => Bold no more! See more here... + # + # strip_tags("
Welcome to my website!
") + # # => Welcome to my website! + def strip_tags(html) + return html if html.blank? || !html.index("<") + tokenizer = HTML::Tokenizer.new(html) + + text = returning [] do |text| + while token = tokenizer.next + node = HTML::Node.parse(nil, 0, 0, token, false) + # result is only the content of any Text nodes + text << node.to_s if node.class == HTML::Text + end + end + + # strip any comments, and if they have a newline at the end (ie. line with + # only a comment) strip that too + result = text.join.gsub(/[\n]?/m, "") + + # Recurse - handle all dirty nested tags + result == html ? result : strip_tags(result) + end + + # Strips all link tags from +text+ leaving just the link text. + # + # ==== Examples + # strip_links('Ruby on Rails') + # # => Ruby on Rails + # + # strip_links('Please e-mail me at me@email.com.') + # # => Please e-mail me at me@email.com. + # + # strip_links('Blog: Visit.') + # # => Blog: Visit + def strip_links(html) + if !html.blank? && (html.index("") + tokenizer = HTML::Tokenizer.new(html) + result = returning [] do |result| + while token = tokenizer.next + node = HTML::Node.parse(nil, 0, 0, token, false) + result << node.to_s unless node.is_a?(HTML::Tag) && ["a", "href"].include?(node.name) + end + end.join + result == html ? result : strip_links(result) # Recurse - handle all dirty nested links + else + html + end + end + + # A regular expression of the valid characters used to separate protocols like + # the ':' in 'http://foo.com' + @@sanitized_protocol_separator = /:|(�*58)|(p)|(%|%)3A/ + mattr_accessor :sanitized_protocol_separator, :instance_writer => false + + # Specifies a Set of HTML attributes that can have URIs. + @@sanitized_uri_attributes = Set.new(%w(href src cite action longdesc xlink:href lowsrc)) + mattr_reader :sanitized_uri_attributes + + # Specifies a Set of 'bad' tags that the #sanitize helper will remove completely, as opposed + # to just escaping harmless tags like <font> + @@sanitized_bad_tags = Set.new(%w(script)) + mattr_reader :sanitized_bad_tags + + # Specifies the default Set of tags that the #sanitize helper will allow unscathed. + @@sanitized_allowed_tags = Set.new(%w(strong em b i p code pre tt output samp kbd var sub + sup dfn cite big small address hr br div span h1 h2 h3 h4 h5 h6 ul ol li dt dd abbr + acronym a img blockquote del ins fieldset legend)) + mattr_reader :sanitized_allowed_tags + + # Specifies the default Set of html attributes that the #sanitize helper will leave + # in the allowed tag. + @@sanitized_allowed_attributes = Set.new(%w(href src width height alt cite datetime title class name xml:lang abbr)) + mattr_reader :sanitized_allowed_attributes + + # Specifies the default Set of acceptable css properties that #sanitize and #sanitize_css will accept. + @@sanitized_allowed_css_properties = Set.new(%w(azimuth background-color border-bottom-color border-collapse + border-color border-left-color border-right-color border-top-color clear color cursor direction display + elevation float font font-family font-size font-style font-variant font-weight height letter-spacing line-height + overflow pause pause-after pause-before pitch pitch-range richness speak speak-header speak-numeral speak-punctuation + speech-rate stress text-align text-decoration text-indent unicode-bidi vertical-align voice-family volume white-space + width)) + mattr_reader :sanitized_allowed_css_properties + + # Specifies the default Set of acceptable css keywords that #sanitize and #sanitize_css will accept. + @@sanitized_allowed_css_keywords = Set.new(%w(auto aqua black block blue bold both bottom brown center + collapse dashed dotted fuchsia gray green !important italic left lime maroon medium none navy normal + nowrap olive pointer purple red right solid silver teal top transparent underline white yellow)) + mattr_reader :sanitized_allowed_css_keywords + + # Specifies the default Set of allowed shorthand css properties for the #sanitize and #sanitize_css helpers. + @@sanitized_shorthand_css_properties = Set.new(%w(background border margin padding)) + mattr_reader :sanitized_shorthand_css_properties + + # Specifies the default Set of protocols that the #sanitize helper will leave in + # protocol attributes. + @@sanitized_allowed_protocols = Set.new(%w(ed2k ftp http https irc mailto news gopher nntp telnet webcal xmpp callto feed svn urn aim rsync tag ssh sftp rtsp afs)) + mattr_reader :sanitized_allowed_protocols + + module ClassMethods #:nodoc: + def self.extended(base) + class << base + # we want these to be class methods on ActionView::Base, they'll get mattr_readers for these below. + [:sanitized_protocol_separator, :sanitized_uri_attributes, :sanitized_bad_tags, :sanitized_allowed_tags, + :sanitized_allowed_attributes, :sanitized_allowed_css_properties, :sanitized_allowed_css_keywords, + :sanitized_shorthand_css_properties, :sanitized_allowed_protocols, :sanitized_protocol_separator=].each do |prop| + delegate prop, :to => SanitizeHelper + end + end + end + + # Adds valid HTML attributes that the #sanitize helper checks for URIs. + # + # Rails::Initializer.run do |config| + # config.action_view.sanitized_uri_attributes = 'lowsrc', 'target' + # end + # + def sanitized_uri_attributes=(attributes) + Helpers::SanitizeHelper.sanitized_uri_attributes.merge(attributes) + end + + # Adds to the Set of 'bad' tags for the #sanitize helper. + # + # Rails::Initializer.run do |config| + # config.action_view.sanitized_bad_tags = 'embed', 'object' + # end + # + def sanitized_bad_tags=(attributes) + Helpers::SanitizeHelper.sanitized_bad_tags.merge(attributes) + end + # Adds to the Set of allowed tags for the #sanitize helper. + # + # Rails::Initializer.run do |config| + # config.action_view.sanitized_allowed_tags = 'table', 'tr', 'td' + # end + # + def sanitized_allowed_tags=(attributes) + Helpers::SanitizeHelper.sanitized_allowed_tags.merge(attributes) + end + + # Adds to the Set of allowed html attributes for the #sanitize helper. + # + # Rails::Initializer.run do |config| + # config.action_view.sanitized_allowed_attributes = 'onclick', 'longdesc' + # end + # + def sanitized_allowed_attributes=(attributes) + Helpers::SanitizeHelper.sanitized_allowed_attributes.merge(attributes) + end + + # Adds to the Set of allowed css properties for the #sanitize and #sanitize_css heleprs. + # + # Rails::Initializer.run do |config| + # config.action_view.sanitized_allowed_css_properties = 'expression' + # end + # + def sanitized_allowed_css_properties=(attributes) + Helpers::SanitizeHelper.sanitized_allowed_css_properties.merge(attributes) + end + + # Adds to the Set of allowed css keywords for the #sanitize and #sanitize_css helpers. + # + # Rails::Initializer.run do |config| + # config.action_view.sanitized_allowed_css_keywords = 'expression' + # end + # + def sanitized_allowed_css_keywords=(attributes) + Helpers::SanitizeHelper.sanitized_allowed_css_keywords.merge(attributes) + end + + # Adds to the Set of allowed shorthand css properties for the #sanitize and #sanitize_css helpers. + # + # Rails::Initializer.run do |config| + # config.action_view.sanitized_shorthand_css_properties = 'expression' + # end + # + def sanitized_shorthand_css_properties=(attributes) + Helpers::SanitizeHelper.sanitized_shorthand_css_properties.merge(attributes) + end + + # Adds to the Set of allowed protocols for the #sanitize helper. + # + # Rails::Initializer.run do |config| + # config.action_view.sanitized_allowed_protocols = 'ssh', 'feed' + # end + # + def sanitized_allowed_protocols=(attributes) + Helpers::SanitizeHelper.sanitized_allowed_protocols.merge(attributes) + end + end + + private + def contains_bad_protocols?(attr_name, value) + sanitized_uri_attributes.include?(attr_name) && + (value =~ /(^[^\/:]*):|(�*58)|(p)|(%|%)3A/ && !sanitized_allowed_protocols.include?(value.split(sanitized_protocol_separator).first)) + end + end + end +end diff --git a/actionpack/lib/action_view/helpers/text_helper.rb b/actionpack/lib/action_view/helpers/text_helper.rb index adb0e1fa1b..d0c8f155ea 100644 --- a/actionpack/lib/action_view/helpers/text_helper.rb +++ b/actionpack/lib/action_view/helpers/text_helper.rb @@ -7,11 +7,7 @@ module ActionView # and transforming strings, which can reduce the amount of inline Ruby code in # your views. These helper methods extend ActionView making them callable # within your template files. - module TextHelper - def self.included(base) - base.extend(ClassMethods) - end - + module TextHelper # The preferred method of outputting text in your views is to use the # <%= "text" %> eRuby syntax. The regular _puts_ and _print_ methods # do not operate as expected in an eRuby code block. If you absolutely must @@ -316,163 +312,6 @@ module ActionView when :urls then auto_link_urls(text, href_options, &block) end end - - # Strips all link tags from +text+ leaving just the link text. - # - # ==== Examples - # strip_links('Ruby on Rails') - # # => Ruby on Rails - # - # strip_links('Please e-mail me at me@email.com.') - # # => Please e-mail me at me@email.com. - # - # strip_links('Blog: Visit.') - # # => Blog: Visit - def strip_links(html) - if !html.blank? && (html.index("") - tokenizer = HTML::Tokenizer.new(html) - result = returning [] do |result| - while token = tokenizer.next - node = HTML::Node.parse(nil, 0, 0, token, false) - result << node.to_s unless node.is_a?(HTML::Tag) && ["a", "href"].include?(node.name) - end - end.join - result == html ? result : strip_links(result) # Recurse - handle all dirty nested links - else - html - end - end - - # This #sanitize helper will html encode all tags and strip all attributes that aren't specifically allowed. - # It also strips href/src tags with invalid protocols, like javascript: especially. It does its best to counter any - # tricks that hackers may use, like throwing in unicode/ascii/hex values to get past the javascript: filters. Check out - # the extensive test suite. - # - # <%= sanitize @article.body %> - # - # You can add or remove tags/attributes if you want to customize it a bit. See ActionView::Base for full docs on the - # available options. You can add tags/attributes for single uses of #sanitize by passing either the :attributes or :tags options: - # - # Normal Use - # - # <%= sanitize @article.body %> - # - # Custom Use - # - # <%= sanitize @article.body, :tags => %w(table tr td), :attributes => %w(id class style) - # - # Add table tags - # - # Rails::Initializer.run do |config| - # config.action_view.sanitized_allowed_tags = 'table', 'tr', 'td' - # end - # - # Remove tags - # - # Rails::Initializer.run do |config| - # config.after_initialize do - # ActionView::Base.sanitized_allowed_tags.delete 'div' - # end - # end - # - # Change allowed attributes - # - # Rails::Initializer.run do |config| - # config.action_view.sanitized_allowed_attributes = 'id', 'class', 'style' - # end - # - def sanitize(html, options = {}) - return html if html.blank? || !html.include?('<') - attrs = options.key?(:attributes) ? Set.new(options[:attributes]).merge(sanitized_allowed_attributes) : sanitized_allowed_attributes - tags = options.key?(:tags) ? Set.new(options[:tags] ).merge(sanitized_allowed_tags) : sanitized_allowed_tags - returning [] do |new_text| - tokenizer = HTML::Tokenizer.new(html) - parent = [] - while token = tokenizer.next - node = HTML::Node.parse(nil, 0, 0, token, false) - new_text << case node - when HTML::Tag - if node.closing == :close - parent.shift - else - parent.unshift node.name - end - node.attributes.keys.each do |attr_name| - value = node.attributes[attr_name].to_s - if !attrs.include?(attr_name) || contains_bad_protocols?(attr_name, value) - node.attributes.delete(attr_name) - else - node.attributes[attr_name] = attr_name == 'style' ? sanitize_css(value) : CGI::escapeHTML(value) - end - end if node.attributes - tags.include?(node.name) ? node : nil - else - sanitized_bad_tags.include?(parent.first) ? nil : node.to_s.gsub(/these tags!") - # # => Strip these tags! - # - # strip_tags("Bold no more! See more here...") - # # => Bold no more! See more here... - # - # strip_tags("
Welcome to my website!
") - # # => Welcome to my website! - def strip_tags(html) - return html if html.blank? || !html.index("<") - tokenizer = HTML::Tokenizer.new(html) - - text = returning [] do |text| - while token = tokenizer.next - node = HTML::Node.parse(nil, 0, 0, token, false) - # result is only the content of any Text nodes - text << node.to_s if node.class == HTML::Text - end - end - - # strip any comments, and if they have a newline at the end (ie. line with - # only a comment) strip that too - result = text.join.gsub(/[\n]?/m, "") - - # Recurse - handle all dirty nested tags - result == html ? result : strip_tags(result) - end # Creates a Cycle object whose _to_s_ method cycles through elements of an # array every time it is called. This can be used for example, to alternate @@ -569,147 +408,6 @@ module ActionView end end - # A regular expression of the valid characters used to separate protocols like - # the ':' in 'http://foo.com' - @@sanitized_protocol_separator = /:|(�*58)|(p)|(%|%)3A/ - mattr_accessor :sanitized_protocol_separator, :instance_writer => false - - # Specifies a Set of HTML attributes that can have URIs. - @@sanitized_uri_attributes = Set.new(%w(href src cite action longdesc xlink:href lowsrc)) - mattr_reader :sanitized_uri_attributes - - # Specifies a Set of 'bad' tags that the #sanitize helper will remove completely, as opposed - # to just escaping harmless tags like <font> - @@sanitized_bad_tags = Set.new(%w(script)) - mattr_reader :sanitized_bad_tags - - # Specifies the default Set of tags that the #sanitize helper will allow unscathed. - @@sanitized_allowed_tags = Set.new(%w(strong em b i p code pre tt output samp kbd var sub - sup dfn cite big small address hr br div span h1 h2 h3 h4 h5 h6 ul ol li dt dd abbr - acronym a img blockquote del ins fieldset legend)) - mattr_reader :sanitized_allowed_tags - - # Specifies the default Set of html attributes that the #sanitize helper will leave - # in the allowed tag. - @@sanitized_allowed_attributes = Set.new(%w(href src width height alt cite datetime title class name xml:lang abbr)) - mattr_reader :sanitized_allowed_attributes - - # Specifies the default Set of acceptable css properties that #sanitize and #sanitize_css will accept. - @@sanitized_allowed_css_properties = Set.new(%w(azimuth background-color border-bottom-color border-collapse - border-color border-left-color border-right-color border-top-color clear color cursor direction display - elevation float font font-family font-size font-style font-variant font-weight height letter-spacing line-height - overflow pause pause-after pause-before pitch pitch-range richness speak speak-header speak-numeral speak-punctuation - speech-rate stress text-align text-decoration text-indent unicode-bidi vertical-align voice-family volume white-space - width)) - mattr_reader :sanitized_allowed_css_properties - - # Specifies the default Set of acceptable css keywords that #sanitize and #sanitize_css will accept. - @@sanitized_allowed_css_keywords = Set.new(%w(auto aqua black block blue bold both bottom brown center - collapse dashed dotted fuchsia gray green !important italic left lime maroon medium none navy normal - nowrap olive pointer purple red right solid silver teal top transparent underline white yellow)) - mattr_reader :sanitized_allowed_css_keywords - - # Specifies the default Set of allowed shorthand css properties for the #sanitize and #sanitize_css helpers. - @@sanitized_shorthand_css_properties = Set.new(%w(background border margin padding)) - mattr_reader :sanitized_shorthand_css_properties - - # Specifies the default Set of protocols that the #sanitize helper will leave in - # protocol attributes. - @@sanitized_allowed_protocols = Set.new(%w(ed2k ftp http https irc mailto news gopher nntp telnet webcal xmpp callto feed svn urn aim rsync tag ssh sftp rtsp afs)) - mattr_reader :sanitized_allowed_protocols - - module ClassMethods #:nodoc: - def self.extended(base) - class << base - # we want these to be class methods on ActionView::Base, they'll get mattr_readers for these below. - [:sanitized_protocol_separator, :sanitized_uri_attributes, :sanitized_bad_tags, :sanitized_allowed_tags, - :sanitized_allowed_attributes, :sanitized_allowed_css_properties, :sanitized_allowed_css_keywords, - :sanitized_shorthand_css_properties, :sanitized_allowed_protocols, :sanitized_protocol_separator=].each do |prop| - delegate prop, :to => TextHelper - end - end - end - - # Adds valid HTML attributes that the #sanitize helper checks for URIs. - # - # Rails::Initializer.run do |config| - # config.action_view.sanitized_uri_attributes = 'lowsrc', 'target' - # end - # - def sanitized_uri_attributes=(attributes) - Helpers::TextHelper.sanitized_uri_attributes.merge(attributes) - end - - # Adds to the Set of 'bad' tags for the #sanitize helper. - # - # Rails::Initializer.run do |config| - # config.action_view.sanitized_bad_tags = 'embed', 'object' - # end - # - def sanitized_bad_tags=(attributes) - Helpers::TextHelper.sanitized_bad_tags.merge(attributes) - end - # Adds to the Set of allowed tags for the #sanitize helper. - # - # Rails::Initializer.run do |config| - # config.action_view.sanitized_allowed_tags = 'table', 'tr', 'td' - # end - # - def sanitized_allowed_tags=(attributes) - Helpers::TextHelper.sanitized_allowed_tags.merge(attributes) - end - - # Adds to the Set of allowed html attributes for the #sanitize helper. - # - # Rails::Initializer.run do |config| - # config.action_view.sanitized_allowed_attributes = 'onclick', 'longdesc' - # end - # - def sanitized_allowed_attributes=(attributes) - Helpers::TextHelper.sanitized_allowed_attributes.merge(attributes) - end - - # Adds to the Set of allowed css properties for the #sanitize and #sanitize_css heleprs. - # - # Rails::Initializer.run do |config| - # config.action_view.sanitized_allowed_css_properties = 'expression' - # end - # - def sanitized_allowed_css_properties=(attributes) - Helpers::TextHelper.sanitized_allowed_css_properties.merge(attributes) - end - - # Adds to the Set of allowed css keywords for the #sanitize and #sanitize_css helpers. - # - # Rails::Initializer.run do |config| - # config.action_view.sanitized_allowed_css_keywords = 'expression' - # end - # - def sanitized_allowed_css_keywords=(attributes) - Helpers::TextHelper.sanitized_allowed_css_keywords.merge(attributes) - end - - # Adds to the Set of allowed shorthand css properties for the #sanitize and #sanitize_css helpers. - # - # Rails::Initializer.run do |config| - # config.action_view.sanitized_shorthand_css_properties = 'expression' - # end - # - def sanitized_shorthand_css_properties=(attributes) - Helpers::TextHelper.sanitized_shorthand_css_properties.merge(attributes) - end - - # Adds to the Set of allowed protocols for the #sanitize helper. - # - # Rails::Initializer.run do |config| - # config.action_view.sanitized_allowed_protocols = 'ssh', 'feed' - # end - # - def sanitized_allowed_protocols=(attributes) - Helpers::TextHelper.sanitized_allowed_protocols.merge(attributes) - end - end - private # The cycle helpers need to store the cycles in a place that is # guaranteed to be reset every time a page is rendered, so it @@ -776,11 +474,6 @@ module ActionView end end end - - def contains_bad_protocols?(attr_name, value) - sanitized_uri_attributes.include?(attr_name) && - (value =~ /(^[^\/:]*):|(�*58)|(p)|(%|%)3A/ && !sanitized_allowed_protocols.include?(value.split(sanitized_protocol_separator).first)) - end end end end -- cgit v1.2.3